treat them like R_PPC_ADDR32
XXX
these relocs have been observed in the xf86-video-radeon driver, but only in
the AtomBios support code, which is unused on PowerPC. This allows the driver
to load but it's not clear if the affected parts would actually function.
rtld and libc use different storage, so the initial version would
incorrectly report the failure reason for fork().
There is still a small race condition inside ld.elf_so as it doesn't use
thread-safe errno internally, but that's a more contained internal
issue.
in a consistent state. This most importantly avoids races between dlopen
and friends and fork, potentially resulting in dead locks in the child
when it itself tries to acquire locks.
on a linker common page size boundary. However, if the common page size
used by the linker is less than the VM page size being used by the kernel,
this can end up in the middle of a VM page and when the region is write-
protected, this can cause objects in neighboring .data to get incorrectly
write-protected, resulting in a crash.
Avoid this situation by calculating the end of the RELRO region not by
rounding memsz up to the VM page size, but rather by adding vaddr + memsz
and then truncating to the VM page size.
Fixes PR toolchain/55043.
XXX pullup-9
DT_GNU_HASH serves the same purpose as DT_HASH, however it is a distinct
and faster apprach implemented and designed in the GNU toolchain in 2006.
DT_GNU_HASH is preferred whenever available.
Original GNU benchmarks claim 50% faster dynamic linking time.
https://www.sourceware.org/ml/binutils/2006-06/msg00418.html
Code based on FreeBSD and OpenBSD, both were based on DragonFlyBSD.
Define Elf_Hash struct that contains ELF/SYSV and GNU hash checksum.
Implement _rtld_gnu_hash() for DT_GNU_HASH.
Adapt existing code to compute all Elf_Hash types, instead of only
the ELF/SYSV one.
Rename _rtld_elf_hash() to _rtld_sysv_hash() to match the GNU toolchain
terminology.
_rtld_gnu_hash() uses Dan Bernstein's string hash function posted eons ago
on comp.lang.c.
The sanitizer does not work reliably before finishing initialization of
ld.elf_so. There is also a number of false positives that are not real
problems here.
on arm after switching to new jemalloc.
jemalloc invokes __tls_get_addr() under some condition. If anything other
than ld.elf_so nor libc exports it, inconsistency arises as a result.
NetBSD.
This brings us resolving for dynamically loaded libraries and makes
tests/libexec/ld.elf_so/t_thread_local_dtor pass.
With suggestions from joerg@
Early ELF binaries defined dlopen and friends in crt0.o by
using function pointers in the object handle passed from rtld.
This contract wastes space when many shared objects are allocated
and ties dynamic linker and rest of the system tightly together.
Fake the entry points in a static object and restrict them to the
platforms that had working ELF support at the time. Keep the magic and
version field used by modern crt0.o for all architectures. The checks
will be removed from crt0.o in a follow-up step.
